This invention is related to the hydrogenation of coal and other hydrocarbonaceous materials for the production of liquid fuels, such as gasoline and jet, turbine and diesel fuels.
A process that has been used for the conversion of coal to liquid products is the H-Coal Process disclosed in U.S. Pat. Nos. 3,519,555 and 3,540,995 which converts coal to gaseous and liquid products by hydrogenation in an ebullated catalyst bed reactor. The present invention is related to improvements in the H-Coal Process and the plant process design and equipment used therein. The present invention is directed to increasing the conversion of coal into valuable hydrocarbon liquid products, such as jet fuels and diesel fuels, by utilizing an on-line hydrotreater, atmospheric and vacuum flash vessels and a solids concentrating and removal means such as a centrifuge for removing solids from the residual oil which is recycled into the reactor, as well as converting gases within the process to provide the hydrogen needed.
The conversion and utilization of coal to produce other more valuable fuel products has been actively carried out for more than half a century. With the advent of the internal combustion engine, and with relatively limited petroleum supplies in some countries of the world, technical efforts were accelerated to convert coal to liquid fuels. In many cases, this work was supported by the military, who realized the need for a dependable supply of liquid fuels in case of war, utilizing available coal deposits.
There are, of course, in the conversion of coal, many mechanical problems in handling coal, as well as the problems of high pressure hydrogenation. It is recognized that coal, as a solid, flows with difficulty. Also, it has a low hydrogen content, and it contains ash. While these obstacles can be overcome technically, the development of a practical economic process for the conversion of coal to more desirable solids-free forms has had many problems involved.
The present invention utilizes a combination of features which make the process for conversion of coal to liquids more efficient, and produes more of the valuable liquid products, such as jet and diesel fuels, and uses the light hydrocarbon gases to generate the hydrogen needed in the process.